The present invention relates to an analysis method and an X-ray photoelectron spectroscope.
An X-ray photoelectron spectroscope (XPS) and an Auger electron microscope (AES) are known as a device that is used to analyze the surface of a solid.
The X-ray photoelectron spectroscope is configured so that photoelectrons emitted from a specimen upon irradiation with X-rays are decelerated and focused on an analyzer by an input lens, and the energy of the photoelectrons are analyzed by the analyzer to obtain a photoelectron spectrum from the specimen.
The photoelectron spectrum obtained by the X-ray photoelectron spectroscope is normally represented by a mixed Gaussian/Lorentzian function (particularly when the analysis target is a light element). In this case, each peak in the photoelectron spectrum corresponds to the chemical bonding state, and the area of each peak is proportional to the relative proportion of the chemical bonding state. Therefore, the quantitative value of the element in each chemical bonding state can be obtained by performing a curve fitting calculation process on the photoelectron spectrum (see JP-A-2009-085859, for example).
The photoelectron spectrum of a light element is normally represented by a mixed Gaussian/Lorentzian function (see above). The photoelectron spectrum of a light element is characterized in that only the position of each peak in the spectrum is shifted even when the chemical bonding state has changed. Therefore, the curve fitting calculation process that uses a mixed Gaussian/Lorentzian function can be appropriately performed on the photoelectron spectrum of a light element.
However, the photoelectron spectrum of a metal that belongs to the fourth or higher period of the periodic table (e.g., transition metal) cannot be appropriately represented by a mixed Gaussian/Lorentzian function. Since the photoelectron spectrum of a transition metal is characterized in that the shift amount of each peak is small when the chemical bonding state has changed, it is difficult to apply the curve fitting process to the photoelectron spectrum of a transition metal.